The present invention relates to footgear including shoes, Japanese geta clogs, slippers, sandals, high heels, and socks, and insoles.
Typically, a heel support formed in footgear or an insole for supporting the heel has an upper surface that is shaped substantially flat or concave in a dish-like manner. As proposed in Japanese Laid-Open Patent Publication No. 2000-83706, a number of projections may project from the upper surface of the heel support. This structure presses and stimulates the bottom surface of the heel, thus promoting blood circulation in the foot.
Japanese Utility Model No. 3026518 discloses an insole for footgear. The insole includes a heel support with a magnet, which presses and stimulates the bottom surface of the heel. Further, Japanese Utility Model No. 3075369 discloses a sock. The sock includes a heel support with a plate-like body, which presses and stimulates the bottom surface of the heel.
Further, footgear or an insole having a shock absorbing material that is provided in a heel support is publicly known.
Normally, as shown in FIG. 9, a human sole includes an inner longitudinal arch A1 located closest to the big toe, an outer longitudinal arch A2 located closest to the little toe, and a lateral arch A3 extending from the base of the big toe to the base of the little toe. The arches A1 to A3 are formed through actions of bones and muscles and form a substantially triangular shape, as viewed from above. However, as the functions of the muscles and tendons of the foot are weakened by aging or illness, the arches A1 to A3 may deform to cause a flatfoot, a clubfoot, a valgus foot, a metatarsus latus, or a bowleg. In walking, flexing motion of the arches A1 to A3 promotes the blood circulation (pumping action) of the foot. Such blood circulation is decreased by the deformation of the arches A1 to A3. Also, the deformation of the arches A1 to A3 increases impact acting on the bone structure of the foot when the heel hits the ground. This increases fatigability of the foot in walking.
The heel supports formed in the conventional footgear and insole press and stimulate the bottom surface of the heel, but cannot correct the deformed arches A1 to A3.